Spraying machine for internal surfaces of hollow articles



Jan. 10, 1956 E. 'r. STOCKER 2,730,070

SPRAYING MACHINE FOR INTERNAL SURFACES OF HOLLOW ARTICLES Filed July 21, 1954 2 Sheets-Sheet 1 FIG I l/l/ll/l/ll/l//////////JI 1 uvvnvrm E. 7. S TOG/(ER nrroRM'y Jan. 10, 1956 E. T. STOCKER 2,730,070

SPRAYING MACHINE FOR INTERNAL SURFACES OF HOLLOW ARTICLES Filed July 21, 1954 2 Sheets-Sheet 2 FIG 3 1 y 64% as a4 WVENmR 5 5. z- STOCKER ATTORNEY United States PatentO SPRAYING MACHINE FOR INTERNAL SURFACES F HOLLOW ARTICLES Application July 21, 1954, Serial No. 444,875

Western N. Y., a

3 Claims.

This invention relates to spraying apparatus, particu larly apparatus for spraying the internal surfaces of hollow articles.

In the manufacture of a certain type of transformer for use in the communication art, cylindrical forms are made of fused quartz, spirally grooved externally for ribbons of copper and produced in pairs, one smaller than the other for interfitting arrangement to produce the desired transformer structure. To produce a shield between the windings of the inner and outer forms, it has been found desirable to coat the inner surface of the larger or outer form with a suitable metal such as silver. However, this presented a difficult problem of applying a substantially uniform coating of a precious metal on the internal surface of a hollow article. 1

The object of the invention is a solution to this problem and the provision of an apparatus which is simple in structure yet highly accurate in spraying the internal 'surface of a hollow article.

With this and other objects in view, the invention comprises an apparatus, including a rotatable support for a hollow article and a spray unit'positioned relative to the support and operable to spray material on the inner surface of the article while the support with the article is rotated. More specifically, the apparatus includes a support for the hollow article which is'movablebetween a spraying position and a loading position. A power means, in the form of an air motor, drives a mechanism to rotate the support with the article at a given speed and to rotate control cams. One of the control cams starts the spray unit at its lowermost position, to spray the lowermost portion of the internal surface of the article, and gradually moves the spraying unit upwardly to completely cover the internal surface with the material. Another cam causes repeated agitation of an element in a receptacle for the material to assure a desired mixture of the vehicle with the silver paste to prevent settling. Another cam controls the air supply to the spray unit while the fourth cam functions to stop a power means at the completion of the spraying operation.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein:

Fig. 1 is a front elevational view of the apparatus, portions thereof being shown in section;

Fig. 2 is a side elevational view of the article support and the mechanism for moving it between its loading and spraying position;

Fig. 3 is a fragmentary rear elevational view of a portion of the apparatus, and

Fig. 4 is a fragmentary sectional view illustrating the cam for the spraying unit. I

In the present embodiment of the invention, the hollow article is cylindrical in general contour and has an inner surface 11 which is to be coated with a suitable material such as silver. The apparatus includes a support 12 adapted to receive and hold the article at a given position with respect to a spray unit 14. The support 12 is fixedly mounted on a spindle 15 which is journalled in a suitable bearing in an angle member 16 and has a bevelled gear 17 mounted on the lower end thereof. The member 16 is supported for rocking movement on a shaft 18 which has bevelled gear 19 fixedly mounted on the adjacent end thereof and interengaging the bevelled gear 17. The shaft 18 is journalled in suitable hearings in a housing 20 and is driven by a suitable power means such as an air operated motor 22. A shaft 23 of the motor 22 drives a worm 24 which interengages a worm gear 25 mounted on the shaft 18; A supply line 28 for air under pressure leads directly to an inlet 29 for the motor 22 and to a normally closed valve 30 for the spray unit 14. An exhaust line 31 for the motor 22 is under the control of a normally open valve 33 through the actuation of its plunger 34 by a spring 35.

A worm 38 mounted on the shaft 18 drives a worm gear 39 which is mounted on a shaft 40. The shaft 40 is journalled in suitable bearings (not shown) and has cams 41, (Fig. l) and 42 (Fig. 4) fixedly mounted thereon in front and back of the worm gear 39 respectively. Another cam 44 is free to rotate on the shaft 40 but is under the control of a pin 45 carried by the cam 41. The cam 41 has high and low portions (as shown in Fig. 1) positioned to be engaged by a cam follower 47, pivoted at 48 and disposed in engagement with a plunger 49 of the valve 30. The low portion of the cam 41 permits the valve 30 to close while the high portion of this cam actuates the follower 47 to move the plunger 49 to open the valve to permit air under pressure to pass through'line 50 to a gun actuating cylinder 51 of the spray unit 14.

The cam 44, during each cycle of the apparatus, is pushed about the axis of the shaft 40 with the cam 41 by the pin 45 engaging a back portion of the cam 44 to cause it to move through a complete cycle. At the completion of this cycle the cam 44 will engage a projection 53 of a lever 54 and move the lever about its pivot 55 and cause it to actuate the plunger 34 of the valve 33. Actuation of the lever 54 to move the valve 33 closed results in stopping the power unit or motor 22.

The cam 42 is of the contour shown in Fig. 4, illustrating the extreme top of its movement of the supporting means for the spray unit 14. This supporting means, as illustrated in Figs. 1, 3 and 4, including a rod 60, formed at its lower end to ride on the surface of the cam 42 and having its upper end mounted in a sleeve 61 which is disposed in a tubular guide 62 mounted in an aperture in the housing 20. A longitudinal groove 63, in the sleeve 61 associated with a pin 64, assures holding of the rod and sleeve against rotation during longitudinal movement thereof by the cam 42. The rod is urged downwardly normally by a spring 66 (as shown in Fig. 3). The upper end of the rod 60 is fixed at 67 to a member 68 which is secured to the spray unit 14 in a suitable manner (not shown). Through this mechanism, the spray unit is moved from its starting position to its finishing position.

The spray unit is of a commercially known type-and the details of its'structure need not be described. However, another unit has been added to the spray unit or to the material supply therefor, including a disc agitator 70 disposed in a receptacle '71 for material 72. The receptacle 71 is connected in the conventional manner 73 to the spray unit 14, preferably at an off center connection with a cover 74 for the receptacle 72. The agitator disc 70 is supported by a stiff but flexible wire 75 extending through a conventional flexible tube 77, one end of which is fixed to the cover 74 in any manner (not shown), while the other end is fixed to a member 78 of a tubular housing 79 mounted at 80 on the main housing 20. The other end of the wire 75 is fixed at $1 to a rod 32 having a head 33 fixed thereto and normally urged downwardly by a spring 84. A cam 35, of the contour shown in Fig. 3, is fixedly mounted on the shaft 18 and rotates therewith to cause constant reciprocation of the rod 82 to translate similar movement through the wire to the disc 70 to force the vehicle of the material 72 downwardly, rapidly into the lower corners of the container to flush out all silver sediment while the violent eddying of the material about the edge of the disc keeps the silver and powdered glass of the silver paste thoroughly mixed. This action takes place during movement of the receptacle with '71 with the spray unit 14.

The means to manually move the support 12 between its loading position, shown in solid lines in Fig. 2, and its spraying position, shown in dotted lines in this figure, includes a hand lever 99 fixed to a spindle 91 journalled in a suitable bearing 92 mounted in the housing 20. The hand lever is adapted to rock lever-like arms 93 and 94. The arm 93 is connected through a link 95 to the angle member 16 at 96. The connecting pivot 97, between the arm 93 and the link 95, may be moved beyond the dead center or beyond a plane between the pivot 96 and the axis of the spindle 91 when in the dotted line position, to lock the support 12 in the spraying position. A negator spring unit 98, having one end portion disposed on the pivot 96 and the other end portion disposed on a pin 99, serves to supply the necessary force to move the support 12 into its loading position and hold it in this position when the locking effect of the arm 93 and the link 95 is released The spring 98 is of a commercially known type, formed of initially fiat spring steel with closely spiraled end portions at the pins 96 and 99 to unwind under force during movement of the support 12 into the spraying position and to wind about their pins while the support is moving into its loading position. The arm 94 carries a finger 104} normally urged clockwise (Fig. 2) by a suitable spring means at its pivot 191 to cause its lower end 102 to ride on the face of cam 41 and to allow cam 44 to pass therebetween.

Considering now the operation of the apparatus, attention is first directed to an air-line 105 where air under a suitable pressure is supplied directly to the unit 14, but in order for the unit to function, the normally closed cylinder 51 must be actuated into open position. The apparatus, as shown in Fig. 1, has just completed one cycle of operation. The cam follower 47 has left the high portion of the cam 41 and moved to the low portion thereof allowing valve to close, cutting off air supply to the cylinder 51 of the spray unit 14. The pin 45 (Fig. 1) has moved the cam 44 into engagement with the projection 53 of the lever 54 to cause the lever to close valve 33 to stop motor 22. This stops operation of all the other units and, at this time, the operator may actuate the lever 90 to move the support 12 from the dotted line spraying position (Fig. 2) to the solid line loading position. The coated article it may be removed from the support and another article inserted in place. During movement of the lever 99 to swing the support from its spraying position to its loading position, the finger 100 is moved upwardly to position its lower end 192 above the adjacent portion of the cam 44.

After the coated article 10 has been removed and the new article inserted in place in the support, the lever 90 may be moved clockwise (Fig. 2) from the solid line position to the dotted line position, to return the support to the spraying position. During this action of the lever 99, the finger 1% will engage the cam 44 and move it beyond the projection 53 so that the spring 35 may function to open the valve 33 to cause operation of the motor 22. As soon as the motor starts operating, the shaft 18 will be rotated, rotating the shaft with the cams 41 and 42. The support 12 will be rotated to rotate the article, but, no spraying action takes place until the spray unit 14 is lowered, by the rod 69 (Fig. 4) riding on the straight portion 105 to return the spray unit to its starting or lower position, During this interval of time, the cam follower 47 rides on the low portion of the cam 41 and at a given time when the unit 14 is in its lower or starting position, the

valve 3% will be moved into its open position to cause operation of the air cylinder 51 to operate the unit 14 to start the spraying operation. The spraying operation begins as indicated by dotted line 106 and during continuous rotation of the support 12 with the article lit), the unit 14 through the action of cam 42 is moved slowly upwardly to the finishing position indicated at 197. All during rotation of the shaft 13, cam 85 through its associated rod 32 and wire will cause agitation of the disc 7% to assure thorough mixing of the material. This mixing operation begins prior to the spraying operation and continues all during the spraying operation. The moment the spraying operation has been completed, the cam 44 will be moved by the pin 45 to actuate the lever 54 to close the valve 33 and stop the motor 22.

These operating cycles will continue substantially automatically requiring only the manual action of the lever 99 to move the support 12 into the loading position to remove a coated article and insert another article to be coated and returning the support through the action of the lever 9t) to the spraying position. Through this action, the cycle of operation of the apparatus begins and carries out, step by step, automatically until the completion of the spraying of the article, at which time, the apparatus automatically stops and waits for the unloading of the sprayed article and the insertion of another article before the spraying cycle again begins its automatic action.

It is to be understood that the above described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrange ments may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. An apparatus for spraying the internal surfaces of hollow articles comprising a drive shaft, power means operable to drive the shaft, an arm supported by the shaft for free rocking movement about the axis thereof, a support for a hollow article rotatably carried by the arm and operatively connected to the shaft to be rotatably driven thereby, means actuable to rock the arm to rock the support therewith between a loading position, where hollow articles may be loaded successively on the support, and a spraying position, a spray unit disposed relative to the support when in the spraying position to direct a spray of material into the article, means driven by the drive shaft in timed relation with the rotation of the support to move the spray unit between a starting position and a finishing position, and means driven by the drive shaft to render the power means unoperated to stop rotation of the drive shaft after a predetermined number of cycles of rotation of the support.

2. An apparatus for spraying the internal surfaces of hollow articles comprising a drive shaft, power means operable to drive the shaft, an arm supported by the shaft for free rocking movement about the axis thereof, a support for a hollow article rotatably carried by the arm and operatively connected to the shaft to be rotatably driven thereby, means actuable to rock the arm to rock the support therewith between a loading position, where hollow articles may be loaded successively on the support, and a spraying position, a spray unit disposed relative to the support when in the spraying position to direct a spray of material into the article, means driven by the drive shaft in timed relation with the rotation of the support to move the spray unit between a starting position and a finishing position, means driven by the drive shaft to render the power means unoperated to stop rotation of the drive shaft after a predetermined number of cycles of rotation of the support, and an element actuable by the means to rock the arm and support to cause operation of the power means when the arm and the support are movedinto the spraying position.

3. An apparatus for spraying the internal surfaces of hollow articles comprising a drive shaft, power means operable to drive the shaft, an arm supported by the shaft for free rocking movement about the axis thereof, a support for a hollow article rotatably carried by the arm and operatively connected to the shaft to be rotatably driven thereby, means actuable to rock the arm to rock the support therewith between a loading position, where hollow articles may be loaded successively on the support, and a spraying position, a spray unit disposed relative to the support when in the spraying position to direct a spray of material into the article, means driven by the drive shaft in timed relation with the rotation of the support to move the spray unit between a starting position and a finishing position, a container for the material supported References Cited in the file of this patent UNITED STATES PATENTS 2,141,630 Westin Dec. 27, 1938 2,342,307 Smith Feb. 22, 1944 2,383,023 Sykes et a1. Aug. 21, 1945 

